LM81CIMT-3

Product Overview

Category

LM81CIMT-3 belongs to the category of integrated circuits (ICs).

Use

This IC is commonly used for temperature monitoring and fan control in electronic devices.

Characteristics

• Temperature monitoring: The LM81CIMT-3 can accurately measure the temperature of its surroundings.
• Fan control: It provides the capability to control the speed of cooling fans based on the measured temperature.
• Low power consumption: The IC operates efficiently, consuming minimal power.
• Small form factor: The LM81CIMT-3 comes in a compact package, making it suitable for space-constrained applications.

Package

The LM81CIMT-3 is available in a small outline integrated circuit (SOIC) package.

Essence

The essence of LM81CIMT-3 lies in its ability to monitor temperature and control fans, ensuring optimal thermal management in electronic devices.

Packaging/Quantity

The LM81CIMT-3 is typically sold in reels containing a specified quantity of ICs. The exact quantity may vary depending on the manufacturer or supplier.

Specifications

• Supply Voltage: 2.7V to 5.5V
• Temperature Measurement Range: -55°C to +125°C
• Resolution: 0.125°C
• Fan Control Output: PWM or DC voltage
• Communication Interface: I2C/SMBus compatible
• Operating Temperature Range: -40°C to +85°C

Detailed Pin Configuration

The LM81CIMT-3 has a total of 16 pins, each serving a specific function. Here is the detailed pin configuration:

1. VDD: Power supply input
2. GND: Ground reference
3. SDA: Serial data line for I2C communication
4. SCL: Serial clock line for I2C communication
5. ALERT: Interrupt output for temperature threshold crossing detection
6. TACH1: Tachometer input for fan speed monitoring
7. TACH2: Tachometer input for additional fan speed monitoring
8. PWM1: Pulse-width modulation (PWM) output for fan control
9. PWM2: Additional PWM output for fan control
10. VDDA: Analog power supply input
11. AIN0: Analog input for temperature sensing
12. AIN1: Additional analog input for temperature sensing
13. AIN2: Third analog input for temperature sensing
14. AIN3: Fourth analog input for temperature sensing
15. VSSA: Analog ground reference
16. NC: No connection

Functional Features

The LM81CIMT-3 offers the following functional features:

1. Temperature Monitoring: The IC can accurately measure temperature using its built-in analog inputs.
2. Fan Control: It provides PWM or DC voltage outputs to control the speed of cooling fans based on the measured temperature.
3. Threshold Detection: The LM81CIMT-3 can generate an interrupt signal when the temperature crosses a predefined threshold.
4. Multiple Inputs: It supports up to four analog inputs for temperature sensing, allowing monitoring of multiple temperature points.
5. Compatibility: The IC is compatible with the I2C/SMBus communication interface, enabling easy integration into existing systems.

Advantages and Disadvantages

Advantages

• Accurate temperature measurement
• Efficient fan control for optimal thermal management
• Small form factor for space-constrained applications
• Multiple analog inputs for versatile temperature sensing

Disadvantages

• Limited temperature range (-55°C to +125°C)
• Requires external components for fan control implementation
• Relatively complex pin configuration may require careful PCB layout design

Working Principles

The LM81CIMT-3 operates by measuring the voltage across its analog inputs, which corresponds to the temperature being monitored. It converts this voltage into a digital value using an internal analog-to-digital converter (ADC). Based on the measured temperature, the IC generates appropriate control signals for fan speed regulation.

Detailed Application Field Plans

The LM81CIMT-3 finds applications in various fields, including:

1. Personal Computers: It is used to monitor and control the temperature of computer components such as CPUs, GPUs, and hard drives.
2. Servers and Data Centers: The IC ensures efficient cooling in server racks and data centers, preventing overheating and maintaining optimal performance.
3. Consumer Electronics: It is employed in devices like gaming consoles, set-top boxes, and home theater systems to regulate temperature and prevent thermal damage.
4. Automotive Electronics: The LM81CIMT-3 is utilized in automotive applications to monitor temperature in engine compartments, battery management systems, and climate control units.

Detailed and Complete Alternative Models

1. LM75A: This digital temperature sensor offers similar functionality but lacks fan control capabilities.
2. MAX31725: It provides